Efficacy of Bidens pilosa Extract against Herpes Simplex Virus Infection In Vitro and In Vivo
Effects of the extract in inhibition of plaque formation and on reduction of virus yield. (a) Effect of the extract in inhibition of plaque formation. Vero cell monolayers were infected with HSV-1 and HSV-2 in the presence of various concentrations of B. pilosa extract. After 1 h incubation for virus adsorption, the prescription was washed out and cells were overlaid with an overlay medium containing the extract for 72 h period of infection. Data are % of control and represent mean ± SD of triplicate cultures. (b) Treatment with 1000 μg/mL B. pilosa extract decreased the number and size of plaques. (c) Effect of the extract on reduction of virus yield. Vero cell monolayers were infected with HSV-1 and HSV-2 and left for adsorption for 1 h. They were washed and overlaid with an overlay medium containing 1000 μg/mL of B. pilosa extract. At the indicated hours postinfection, both cell-associated and extracellular viruses were titrated by the plaque assay.